he responded:
>> Check John Burns, from Islamabad, New York Times, Sept. 16. About
>> half way through is the following sentence:
>> Washington has also demanded a cutoff of fuel supplies, an end to
>> the use of Pakistani banks as conduits for clandestine money
>> movements by terrorists and the elimination of truck convoys that
>> provide much of the food and other supplies to Afghanistan's
>> civilian population.
http://archive.nytimes.com/2001/09/16/international/asia/16PAKI.html
i also found this article (dated 9/18) in a more recent search:
PAKISTAN-AFGHANISTAN: HUMANITARIAN CRISIS BUILDS http://www.globalinfo.org/eng/reader.asp?ArticleId=9510
"The clearance and all transportation of food, other consumer goods and equipment imported by Afghan traders from abroad or Pakistan has been suspended with the immediate effect," said an official of the Central Bureau of Revenues, which supervises the Afghan Transit Trade Scheme under which Pakistan gives duty-free passage to all goods destined for Afghanistan.
"From (yesterday) onwards, all Afghanistan-bound shipments remain suspended until further orders," he added.
so, question answered (thanks also to info from Charles Jannuzi)